1. Field of the Invention
This invention relates to propulsion apparatus and more particularly to apparatus for converting rotary motion to unidirectional motion.
2. Description of the Prior Art
Systems for converting rotary motion into unidirectional thrust are well known in the art as disclosed in U.S. Pat. Nos. 2,886,976; 3,584,515; 3,968,700; 3,998,107; and 4,095,460. U.S. Pat. No. 2,886,976 discloses the well known "Dean Space Drive" which utilizes oppositely rotating pairs of eccentric inertia masses in a freely suspended system which converts movements provided by a prime mover into either intermittent propulsive pulses or continuous thrust in one direction. When a load is imposed on a system in a central direction so that movement in one direction will act on and move the load, lift or thrust is generated.
In operation of the "Dean Space Drive", a pair of eccentric counterrotating inertial masses are fixed on parallel drive shafts. Primary rotary power is mechanically connected to one, and the other shaft is driven by gears. A frame supporting the two eccentric masses is supported above and below with adjustable springs. The frame is freely suspended in one plane in an outer frame. Rollers, wheels or bearings permit minimal friction between the two frames. A pair of solenoids return the movable frame to the center position during each oscillation and provide damping. A steel tape operates as the load mechanism, and during each positive position of an oscillation it is advanced by an engaged electromagnetic clutch. The solenoid and magnetic clutch are activated in timed relation. The rigid connection between paired shafts and the counter-rotation of the masses produces a concellation of forces and reactions engendered in all directions except in the direction of the desired oscillation. This is always parallel to a plane perpendicular to the axes of rotation of the two masses.
The cancellation of the forces produces an oscillation by the resultant forces which represent the sum of the components of all forces acting in the direction of a plane at right angles to the shaft axes. The generated unidirectional force is transmitted to a load or can act on the carrier itself.
U.S. Pat. No. 3,998,107 discloses a device that converts rotary motion into unidirectional motion by varying the radius or gyration of a plurality of gyrating masses which gyrate in a plane that is perpendicular to the axis of rotation. A rotating drive shaft generates rotation of a support structure and gyrating masses. The axis of the displaced crank segment of the crank-like shaft does not coincide with the axis of rotation of the gyrating masses. Consequently, the radial distance of each gyrating mass varies from some minimum distance to some maximum distance. This results in a variation of the centrifugal force produced by each gyrating mass. The angular position of the cranklike shaft determines the position where the gyrating masses attain the maximum and minimum radial distances.
U.S. Pat. No. 3,584,515 discloses a system for varying the radius of gyration of a plurality of masses as they pass through a predetermined sector of the path of rotation. Consequently an unbalanced centrifugal force propels a frame in a direction which depends on the application of the sector at which the unbalance occurs. Compressed air is utilized to effect movement of the pistons and the associated liquid masses. The control means for effecting movement of the pistons at a particular point in their rotational travel about the axes to create the unbalanced centrifugal force includes switches actuated by a knob to energize gate valves to, in turn, energize solenoids associated with the operation of the switches.
U.S. Pat. Nos. 3,968,700 and 4,095,460 also disclose devices for converting rotary motion to unidirectional motion by varying the radius of gyration of a plurality of masses. The direction of the unbalanced force is selectively changed by the orientation of a pair of cams.
While it is known to convert rotary motion into unidirectional linear motion, the prior art devices rely upon the displacement of a plurality of rotating masses in which the masses are oscillated toward and away from the axis of rotation between a maximum radial distance and a minimum radial distance relative to the axis of rotation. Consequently, unbalanced centrifugal force is generated in a preselected direction, and the direction of the unbalanced centrifugal force is selective. These known devices require complex support and action/reaction construction to generate movement of the rotating masses so that the radius of gyration of each of the masses is constantly changing as the masses pass through a predetermined sector of a path of rotation.
Therefore, there is a need for a propulsion system that converts rotary motion to unidirectional motion to generate an unbalanced centrifugal force without a complicated arrangement of varying the radius of gyration of masses positioned on the circumference of a rotating frame.